The US has been a bulwark for Ukraine. What happens if its support collapses?

A woman walks between the graves of Ukrainian soldiers killed in combat since Russia's February 2022 full-scale invasion of the country, at a military cemetery in Lviv last month. Photograph: Finbarr O'Reilly/New York Times A year ago, when Washington and much of Europe were still awash in optimism that Ukraine was on the verge of repelling Russia from its territory, it seemed inconceivable that the United States would turn its back on the victim of Vladimir Putin's aggression. Now, even as Senate Democrats try to salvage an aid package for Ukraine, that possibility remains real. And the political moment feels…